1. Field of the Invention
This invention relates to a composite video apparatus which can selectively display images from various video signal sources such as, for example, a video CD, a picture MD and a letter and character broadcast.
2. Description of the Related Art
Various video signal sources are available including recording media on which video signals are recorded and broadcasting signals from which video signals can be extracted.
Recording media on which video signals are recorded include, for example, various CDs (compact disks) such as video CDs, photographic CDs and navigation disks which are called CD-ROMs on which various video signals are recorded. Also magneto-optical disks called MDs (mini disks) have been spread widely in recent years, and particularly, mini disks on which not only music but also file data or video data can be recorded have been developed. For example, one of such mini disks called picture MD is used as a medium for recording a video signal.
Further, one of broadcasting signals from which video signals can be extracted is a letter and character broadcast in television broadcasting or FM multiplex broadcasting.
By the way, for a composite AV (audio/visual) apparatus for home use, an apparatus which can selectively output an image from such various image sources as mentioned above is demanded. However, such an apparatus as just mentioned has a problem in that a large circuit scale and a high cost cannot be avoided.
For example, in order to make an apparatus compatible with a video CD, a picture MD and a letter and character broadcast, the apparatus must include decoders and display output memories for the individual video apparatus.
Further, while a CD driver and a CD-ROM decoder for a video CD can be used commonly for other CD-ROMS such as a navigation disk and a photographic CD, special decoding processing is required particularly for a navigation disk. This is because special display control is required from, in addition to a function of displaying map information, another function unique to a navigation system of allowing scrolling display in any direction in response to a manual operation of a user. To this end, an LSI for exclusive use for decoding and display output is used frequently. Consequently, where a composite video apparatus is designed so as to be compatible with a navigation disk, a higher cost is required.